The Department of Biochemistry & Molecular Biology, and the Department of Chemistry at The University of Chicago propose an interdisciplinary predoctoral training program directed at the interface of the chemical and biological sciences. The program will emphasize cross-training and will have a synthetic and mechanistic focus. Predoctoral students will be registered either in the Department of Biochemistry & Molecular Biology in the Biological Sciences Division or in the Department of Chemistry in the Physical Sciences Division, but will pursue through elective coursework a program satisfying the requirements of the M.S. degree in the other division while completing all requirements for the Ph.D. degree in their home division. This program will thus ensure cross-training in the language and research methods of chemistry and biology. In addition, predoctoral students will have at least one research rotation in the laboratory of a participating faculty member in the other division prior to selecting a research advisor. The participating faculty, with established research programs in the general areas of bioorganic, bioinorganic, and biophysical chemistry, as well as synthetic and mechanistic organic chemistry, are often engaged in a variety of collaborative projects involving both chemical and biological techniques. The training program will emphasize the application of concepts of organic, inorganic and physical chemistry to biological problems. The proposed program does not overlap with other NRSA training program currently at The University of Chicago and is a new development in the graduate curricula of both departments. Funds are requested for a predoctoral trainee group of six(6) students with four years of support each, building to a steady-state population of 24 students in the fourth year of the proposal.